The present invention relates to a blind rivet for a threaded joint between a support member and a mounting member.
German utility model DE-GM 90 01 069.8 discloses a blind rivet nut which consists of an external body member of elastic material and a threaded insert of metallic material. The external body member comprises a sleeve-shaped shank adapted to be inserted into a mounting hole of the support member. The shank has a mounting flange and a folding zone adapted to be folded into a fold such that the blind rivet nut is retained at the mounting member by the mounting flange on the one side and by the fold on the other side. The threaded sleeve of the blind rivet nut is divided into a threaded element and a spacer sleeve. The spacer sleeve engages the bottom side of the mounting member at the end of the folding operation. There are also embodiments wherein the threaded sleeve is an integral one-piece part.
In any case, the axial force necessary for the folding operation is transferred from the mounting bolt via the metallic threaded sleeve directly upon the mounting member while the fold needs not to take up the axial force. Nevertheless the prior blind rivet nut is subject to certain strength constraints. If for example the blind rivet nut is to be designed for a threaded joint including a high strength bolt of a strength class of more than 8.8 (according to DIN-JSO 898 part 1), there will be a risk of unacceptable twisting and torsional deformation of the elastic external body member and excessive surface pressure between the end face of the threaded sleeve and the bottom side of the mounting member.